Study suppression of tumor growth with less side effects than traditional therapies by transfer of a foreign gene, cytosine deaminase (CD) into cancer cells within the liver. A modified adenovirus is used to transfer this gene. Inside the cancer cells this gene directs the production of CD protein within the cells allowing these cells to convert the nontoxic antibiotic 5-fluorocytosine (5FC) to the active chemotherapeutic agent 5- fluorouracil (5FU) thereby suppressing their growth.